Stress and survival

The Stress and Survival research theme aims to understand why and how seeds die during storage and/or desiccation, and also determine the factors involved in survival of other stresses such as salt, heat and cold.

The choice of ex situ conservation strategy depends on whether seeds are desiccation tolerant or sensitive. Up to 100,000 species may have seeds that are intolerant of drying. To develop a better estimate of the frequency of species with desiccation sensitive seeds, we are combining geographical information with analysis of seed traits such as mass, seed coat ratio, tolerance of drying, rate of drying, and embryo morphology.

For desiccation tolerant seeds that can be stored under seed bank conditions, the processes that lead to the gradual deterioration of collections are studied. Ageing in all organisms is associated with the accumulation of oxidative damage such as lipid peroxidation and protein and nucleic acid oxidation caused by reactive oxygen species. Our research is:

investigating how cell death processes in seeds differ on a tissue-specific basis, and the role that programmed cell death plays in viability loss in ageing seeds.

utilising omics-based approaches to provide a complete overview of the changes in gene expression, protein expression and metabolite levels that occur as seeds age, and to identify potential markers of seed viability.

developing non-invasive techniques for screening seed collections to assess viability without the need for germination. For example, the volatile compounds released by seeds as they age can be detected using gas chromatography – mass spectroscopy, and this approach may offer a means of detecting the early signs of seed ageing enabling action to be taken before seeds start to die.

testing the possibility that some cells remain viable in seeds that otherwise appear dead (unable to germinate), and that these cells could provide an opportunity to recover germplasm from non-viable seed collections.